Rock-grab.



INVENTOR I Patented Feb. 23, 1915.

J. MADILL.

ROCK GRAB APPLICATION FILED mmzs, 1914,

M w M WITNESSES:

7m NORRIS PE TERS C0,, PHOTG-LITHQ, WASHINGTON. D

JOHN avian-ILL, or rear anrnnn, on'ranxo, cannon.

' ROCK-GRAB.

specification of Letters Patent. Patented Feb. 23, 1915.

Application filed March 23, 1914. Serial No. 826,830,

To all whom it may concern:

Be it known that l, Jenn MADILL, a citizen of the Dominion of Canada,residing at Port Arthur, inthe Province of Ontario, Dominion of Canada,have invented a new and lmproved RocleG-rab, of which the following is aspecification.

This invention, which generally relates to means for loading andunloading, more particularly has reference to grapples, clam shellbuckets and other like means in which the grab or grappling devices arearranged for being raised and lowered by suitable hoisting mechanism.

1My invention primarily has for its purpose to provide an appliance ormeans that is more particularly designed for handling large rock andboulders for public Works, break waters, etc, and in which the grapplingelements may be readily formed with quarter shells or Wings to adapt thesaid appliance or means for digging and hoisting such filling as sand,mud, gravel and shale rock.

Another and essential object of my vention is to provide a grapple ofthe general type stated, in which the grappling hooks or members arecooperatively so mounted upon a single head block whereby to provide forthe utilization of a simple and effective device for equalizing thestrain upon the grappling hooks, and whereby the said grapples arecaused to conform to any irregular objects.

Another object of my invention is to provide a rock grab whose parts areso designed ,to operate under asimple actuating mechanism, and so thatall are protectedas far as possible from injury or from becoming easilydisabled under ordinary uses and joined in such a manner that any partmay be quickly removed and replaced.

With other objects'in view, all of which will be hereinafter explained,my invention is an improved rock grab that embodies the peculiarfeatures of construction and combination of parts, all of which will behereinafter first described, specifically pointed out in the appendedclaims, and illustrated in the accompanying drawing, in which:

Figure 1 is a perspective view of my improved rock grab, the same beingshown at its opened position. Fig. 2 is a top plan view thereof, thegrapple members or hooks being shown at their closed or grabbingposition. Fig. 3 is a vertical section of the same taken on the line 33on Fig. 2. Fig. 4 is a sectionalelevation of the equalizing blockhereinafter referred to, showing the chain connection to the variousgrippers, diagrammatically. Fig. 5 is a diagram matic perspective viewshowing how the grippers adapt themselves to objects of irregularcontour.

In the practical construction, my invention includes a single or headblock casting 1.,formedwith a central circular aperture 10, and fourregularly equally spaced bifurcated extensions arranged in oppositepairs, designated 11-11, 12-l2, respectively, and

each is provided with a transverse bearing for receiving the pivot bolts13-13 upon each of which is pivotally hung the head end 20 of a grab orhook member 2 and having the usual shape, as shown.

14tdesignates the nutsthat engage the bolts 13.

Each grab member or hook 2, at a point near its pivoted head is formedwith a bifurcated inwardly extending bracket 21 within which is locateda chain guide wheel 23, mounted upon the stud pins 4: transverselymounted in the said brackets and which receive the nuts 4:0, as shown.

By suspending the grab hooks independently, from the head block 1, asshown and described, allows the said grab hooks to each workindependently, and to hold them from spreading too far apart, they arejoined by four safety stay chains 6 whose ends are attached to keepers7, one of which is pivotally mounted on each hook.

For distributing an equal closing strain on the four hooks collectively,though they work independently of each other, I use a closing chain thatconsists of two bights or sections designated 8-80, and each of which isin the nature of a pendent loop, the upper or free end of one of which,is connected to one end of a heavy equalizing chain 9 that is suspendedlooplike from a pulley block 22, mounted in a bracket 23 hung on aclevis-like hanger 24: that joins with the lower end ofthe hoist ingcable 25. The other end of the equalizing chain 9 connects with the freeends 81 of the closing chain section 80. It will be noticed the twochain sections 80 and 8 cross each other'where they pass over from oneset of chain guide wheels 33 and the four strands of the said chainsections 80-8 pass up through the central opening in the head block andover guide rollers 15 journaled on the bolts 16 in the bracket-like cars17 cast with the head block, the several rollers 15 being so positioned,relatively to the edge of the said opening, to project suliiciently tokeep the chains from rubbing up against the said edge.

When an object of irregular contour is grabbed as shown in Fig. 5, thehooks will adapt themselves closely to the uneven surface since theclosing chain sections 8 and 80 may draw the hooks together until thehooks have set themselves after which the chain sections 8 and 80 willbe equalized through the medium of the chain section 9 passing over thesheave 22.

18 designates the tripping cable, the lower end of which carries a heavyring 19 with which the several. lift chains 26, one for each grapple orhook member to which the chains connect, as shown.

Each hook or grapple member has a stop lug 27 at the head end that formsa stop for engaging the head block and holding the hooks from beingswung up too high.

From the foregoing taken in connection with the drawing, the completeconstruction and the manner of use of my invention will be readilyunderstood.

It will be readily seen the grapples being at their. opened position,when lowered and power. is applied to the closing chains, there is apowerful pull on the two opposing sets of grapples or hooks and causethem to close in under the rock or other material to be raised, andwhenthe load is grabbed, the hoisting cable elevates the grab with the loadand swings'it to thedumping or unloading point, and the said loaddischarged by pulling on'the trip cables or, chains, and at the sametime slackening the closing chains.

I While I have not shown it, it is obvious that the end of the grapplesmay be fitted with winged blades to adapt them to act as scoops fordigging and lifting soft ma- 'terial.

WVhat I claim is:

1. In a grab of the character described, a single head block, two pairsof oppositely set grappling hooks, each of said hooks beingindependently hung on the head block,

a closing cable for each pair of hooks, an

equalizing means to which the free ends of the said chains connect, ahoisting cable connected to the said means and other means for'trippingthe grappling hooks to swing Copies of this patent may be obtained forthem to their open position as tension 011 the closing cables isreleased.

2. In a grab of the character stated, a head block, a plurality ofgrappling hooks pivotally connected at their upper ends to said headblock, stay connections between the several hooks below the pivots, atrip line flexibly connected with the respective hooks whereby tosustain the said hooks to their open position, a hoisting line, anequalizing block carried by said hoisting line, and closing cablesconnected with the respective hooks and with said equalizing block.

3. In a device of the character stated, a head block, a plurality ofsets of grapples pivotally connected at their upper ends to said headblock, stops limiting the opening movement of said grapples, flexiblespacing members connecting said grapples with each other, a trip cable,separate connections between said cable and the respective grappleswhereby to open up said grapples when the apparatus is suspended by saidcable, an equalizing block carried by said hoisting cable, a closingcable passing through said block and having endless loops one for eachpair of grapples, members carried by said grapples and projecting intosaid loops whereby when the apparatus is supported by said hoistingcable the tension on said closing cable will draw said grapplestogether, substantially as shown and described.

1. In a device of the character stated, a head block, a plurality ofsets of grapples pivotally connected at their upper ends to said headblock, stops limiting the opening movement of said grapples, flexiblespacing members connecting said grapples with each other, a trip cable,separate connections between said cable and the respective grappleswhereby to open up said grapples when the apparatus is suspended by saidcable, an equalizing block carried by said hoisting cable, a closingcable passing through said block and having endless loops one for eachpair of grapples, members carried by said grapples and projecting intosaid loops whereby when the apparatus is supported by said hoistingcable the tension on said closing cable will draw said grapplestogether, and guide rollers on said head block over which said closingcable passes.

JOHN MADILL. 1. s.] Witnesses:

W. E. MUTCH, A. B. BARBER.

five cents each, by addressing the Commissioner of Patents Washington,D. G.

